Online incremental payment method

1. A system for transferring funds between a payor and a payee, the system comprising:

a host computer system; and

a computer readable storage medium having encoded thereon at least one computer-readable program including one or more computer-executable instructions executed on the host computer system, wherein the instructions cause the host computer to:

receive information from the payor identifying a first plurality of payment sources configured by the payor as possible source accounts;

receive information from the payee identifying acceptable types of source accounts;

cull the first plurality of payment sources based at least in part on the acceptable types of source accounts;

transmit the culled first plurality of payment sources to the payor for selection by the payor of a source account;

receive information from the payor for debiting the source account, wherein the information comprises payor personal information including information regarding the source account and information regarding online transaction data including a total amount of the online transaction, and wherein the payor personal information is not exposed to the payee;

transmit to the payee an authorization to request debits from the payor, wherein a total of all debit requests does not exceed the total amount for the online transaction;

receive a first request from the payee to debit the payor a first portion of the total amount for the online transaction;

in response to the first request from the payee, initiate a first debit from the source account to a bank account associated with the payee for the first portion of the amount;

receive a second request from the payee to debit the payor a second portion of the total amount for the online transaction; and

in response to the second request from the payee, initiate a second debit from the source account to the bank account associated with the payee for the second portion of the amount.

2. A system as in claim 1 , wherein the payee comprises a merchant, and further comprising a merchant computer system that is configured to receive the authorization to request debits from the payor.

3. A system as in claim 1 , wherein the computer-readable program further includes instructions to check that a sum of the first debit and the second debit does not exceed the total amount before performing the second-listed initiating step.

4. A system as in claim 1 , wherein the computer-readable program further includes instructions to:

receive information from the payee for crediting the bank account associated with the payee, wherein said information comprises payee personal information including information regarding a payee account;

initiate a first credit to a payee account that corresponds to the first portion of the amount; and

initiate a second credit to a payee account that corresponds to the second portion of the amount.

5. A system as in claim 1 , wherein the computer-readable program further includes instructions to receive information from the payee for crediting a payee account.

6. A system for transferring funds between a first party and a second party, the system comprising:

a host computer system; and

a computer readable storage medium having encoded thereon at least one computer-readable program including one or more computer-executable instructions executed on the host computer system, wherein the computer-executable instructions cause the host computer to:

receive purchase information from the second party that includes a total amount;

receive purchaser information from the first party that includes the total amount;

validate the purchaser information by comparing it at least in part to the received purchase information;

send, to the second party, a digital IOU;

receive, from the second party, the digital IOU;

validate the digital IOU;

receive a plurality of requests from the second party to debit a bank account associated with the first party; and

in response to the plurality of requests from the second party, initiate a plurality of debits from the bank account.

7. A system as in claim 6 , wherein the computer-readable program further includes instructions to check that a sum of the plurality of debits does not exceed the total amount before performing the initiating step.

8. A system as in claim 6 , wherein the computer-readable program further includes instructions to:

receive information from the second party for crediting a second account of the second party, wherein said information comprises personal information associated with the second party including information regarding said second account; and

initiate a plurality of credits to the second account of the second party, wherein the plurality of credits correspond to the plurality of debits.

9. A system as in claim 8 , wherein each of the plurality of credits is less than its corresponding debit by a fee.

10. A system as in claim 6 , wherein the computer-readable program further includes instructions to receive information from the second party for crediting a second account of the second party.

11. A system for transferring funds between a first party and a second party, the system comprising:

a host computer system; and

a computer readable storage medium having encoded thereon at least one computer-readable program including one or more computer-executable instructions executed on the host computer system, wherein the computer-executable instructions cause the host computer to:

receive information from the first party identifying a first plurality of payment sources configured by the first party as possible source accounts;

receive information from the second party identifying acceptable types of source accounts;

culling the first plurality of payment sources based at least in part on the acceptable types of source accounts; and

transmitting the culled first plurality of payment sources to the first party for selection by the first party of a source account;

receive information from the first party for debiting the source account, wherein the information comprises personal information including information regarding the source account and information regarding online transaction data including a total amount of the online transaction, and wherein the personal information is not exposed to the second party;

transmit to the second party an authorization to request debits from the source account, wherein a total of all debit requests does not exceed the total amount;

receive a plurality of requests from the second party to debit the source account; and

in response to the plurality of requests from the second party, initiate a plurality of debits from the source account.

12. A system as in claim 11 , wherein the first party is remote from the second party.

13. A system as in claim 11 , wherein the plurality of debits from the source account are transmitted directly from the source account to a destination account associated with the second party, with no more than one interim party.

14. A system as in claim 11 , wherein:

the computer-executable instructions further cause the host computer to receive purchase information from a first web page, the first web page provided by the second party; and

the information from the first party for debiting the source account is received from a second web page, the second web page provided by the host computer system.

15. A system as in claim 11 , wherein the computer-executable instructions further cause the host computer to transmit to the first party a validation request, wherein the validation request comprises a graphical representation of a negotiable check, the check including at least a portion of the online transaction data including payee, date, and amount.

16. A system as in claim 15 , wherein the first party enters a password into a signature line of the graphical representation of the negotiable check to validate the debiting of the source account.

17. A system as in claim 11 , wherein the host system guarantees payment for the online transaction such that the second party will not be chargedbacked.

18. A system as in claim 17 , wherein guaranteeing payment comprises conducting a risk assessment of the first party, and the risk assessment comprises analyzing past usage of the host computer by the first party.